/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.it.udf;

import org.apache.iotdb.it.env.EnvFactory;
import org.apache.iotdb.it.framework.IoTDBTestRunner;
import org.apache.iotdb.itbase.category.ClusterIT;
import org.apache.iotdb.itbase.category.LocalStandaloneIT;
import org.apache.iotdb.itbase.constant.BuiltinAggregationFunctionEnum;
import org.apache.iotdb.itbase.constant.BuiltinTimeSeriesGeneratingFunctionEnum;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import static org.junit.Assert.*;

@RunWith(IoTDBTestRunner.class)
@Category({LocalStandaloneIT.class, ClusterIT.class})
public class IoTDBUDFManagementIT {

    private static final int NATIVE_FUNCTIONS_COUNT =
            BuiltinAggregationFunctionEnum.getNativeFunctionNames().size();
    private static final int BUILTIN_FUNCTIONS_COUNT =
            BuiltinTimeSeriesGeneratingFunctionEnum.values().length;

    private static final String FUNCTION_TYPE_NATIVE = "native";
    private static final String FUNCTION_TYPE_BUILTIN_UDTF = "built-in UDTF";
    private static final String FUNCTION_TYPE_EXTERNAL_UDTF = "external UDTF";

    @Before
    public void setUp() throws Exception {
        EnvFactory.getEnv().initBeforeTest();
    }

    @After
    public void tearDown() {
        EnvFactory.getEnv().cleanAfterTest();
    }

    @Test
    public void testCreateReflectShowDrop() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
            statement.executeQuery("select udf(*, *) from root.vehicle");

            try (ResultSet resultSet = statement.executeQuery("show functions")) {
                assertEquals(3, resultSet.getMetaData().getColumnCount());
                int count = 0;
                while (resultSet.next()) {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 1; i <= resultSet.getMetaData().getColumnCount(); ++i) {
                        stringBuilder.append(resultSet.getString(i)).append(",");
                    }
                    String result = stringBuilder.toString();
                    if (result.contains(FUNCTION_TYPE_NATIVE)) {
                        continue;
                    }
                    ++count;
                }
                Assert.assertEquals(1 + BUILTIN_FUNCTIONS_COUNT, count);
                statement.execute("drop function udf");
            }
        } catch (SQLException throwable) {
            fail(throwable.getMessage());
        }
    }

    @Test
    public void testCreateAndDropSeveralTimes() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
            statement.executeQuery("select udf(*, *) from root.vehicle");

            try (ResultSet resultSet = statement.executeQuery("show functions")) {
                int count = 0;
                while (resultSet.next()) {
                    ++count;
                }
                Assert.assertEquals(1 + NATIVE_FUNCTIONS_COUNT + BUILTIN_FUNCTIONS_COUNT, count);
                assertEquals(3, resultSet.getMetaData().getColumnCount());
                statement.execute("drop function udf");

                statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
                statement.executeQuery("select udf(*, *) from root.vehicle");
            }

            try (ResultSet resultSet = statement.executeQuery("show functions")) {
                int count = 0;
                while (resultSet.next()) {
                    ++count;
                }
                Assert.assertEquals(1 + NATIVE_FUNCTIONS_COUNT + BUILTIN_FUNCTIONS_COUNT, count);
                assertEquals(3, resultSet.getMetaData().getColumnCount());
                statement.execute("drop function udf");
            }
        } catch (SQLException throwable) {
            fail(throwable.getMessage());
        }
    }

    @Test
    public void testReflectBeforeCreate() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.executeQuery("select udf(*, *) from root.vehicle");
        } catch (SQLException throwable) {
            assertTrue(throwable.getMessage().contains("Failed to reflect UDF instance"));
        }
    }

    @Test
    public void testReflectAfterDrop() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
            statement.execute("drop function udf");
            statement.executeQuery("select udf(*, *) from root.vehicle");
        } catch (SQLException throwable) {
            assertTrue(throwable.getMessage().contains("Failed to reflect UDF instance"));
        }
    }

    @Test
    public void testCreateFunctionWithBuiltinFunctionName1() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function aVg as 'org.apache.iotdb.db.query.udf.example.Adder'");
            fail();
        } catch (SQLException throwable) {
            assertTrue(
                    throwable
                            .getMessage()
                            .contains("the given function name conflicts with the built-in function name"));
        }
    }

    @Test
    public void testCreateFunctionWithBuiltinFunctionName2() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute(
                    "create function MAX_VALUE as 'org.apache.iotdb.db.query.udf.example.Adder'");
            fail();
        } catch (SQLException throwable) {
            assertTrue(
                    throwable
                            .getMessage()
                            .contains("the given function name conflicts with the built-in function name"));
        }
    }

    @Test
    public void testCreateFunction1() throws SQLException { // create function twice
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");

            try {
                statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
                fail();
            } catch (SQLException throwable) {
                assertTrue(throwable.getMessage().contains("Failed to create"));
            }
        }
    }

    @Test
    public void testCreateFunction3() throws SQLException { // create function twice
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");

            try {
                statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
                fail();
            } catch (SQLException throwable) {
                assertTrue(throwable.getMessage().contains("the same name UDF has been created"));
            }
        }
    }

    @Test
    public void testCreateFunctionWithInvalidURI() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            try {
                statement.execute(
                        String.format(
                                "create stateless trigger %s before insert on root.test.stateless.* as '%s' using URI '%s' with (\"name\"=\"%s\")",
                                "a", "org.apache.iotdb.test", "", "test"));
                fail();
            } catch (Exception e) {
                assertTrue(e.getMessage().contains("URI"));
            }

            try {
                statement.execute(
                        String.format(
                                "create stateless trigger %s before insert on root.test.stateless.* as '%s' using URI '%s' with (\"name\"=\"%s\")",
                                "a", "org.apache.iotdb.test", "file:///data/udf/upload-test.jar", "test"));
                fail();
            } catch (Exception e) {
                assertTrue(e.getMessage().contains("URI"));
            }
        } catch (SQLException throwable) {
            fail();
        }
    }

    @Test
    public void testDropFunction1() throws SQLException { // create + drop twice
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");
            statement.execute("drop function udf");

            try {
                // drop UDF that does not exist will not throw exception now.
                statement.execute("drop function udf");
            } catch (SQLException throwable) {
                assertTrue(throwable.getMessage().contains("this UDF has not been created"));
            }
        }
    }

    @Test
    public void testDropFunction2() { // drop
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            // drop UDF that does not exist will not throw exception now.
            statement.execute("drop function udf");
        } catch (SQLException throwable) {
            assertTrue(throwable.getMessage().contains("this UDF has not been created"));
        }
    }

    @Test
    public void testDropBuiltInFunction() throws SQLException { // drop
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            try {
                statement.execute("drop function abs");
                fail();
            } catch (SQLException throwable) {
                assertTrue(
                        throwable.getMessage().contains("Built-in function ABS can not be deregistered"));
            }
            // ensure that abs is not dropped
            statement.execute("INSERT INTO root.vehicle.d1(time, s1) VALUES(1, -10.0)");
            try (ResultSet rs = statement.executeQuery("SELECT ABS(s1) FROM root.vehicle.d1")) {
                Assert.assertTrue(rs.next());
                Assert.assertEquals(1, rs.getLong(1));
                Assert.assertEquals(10.0F, rs.getFloat(2), 0.00001);
                Assert.assertFalse(rs.next());
            }
        }
    }

    @Test
    public void testDropBuiltinFunction1() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("drop function sin");
            fail();
        } catch (SQLException throwable) {
            assertTrue(throwable.getMessage().contains("Built-in function SIN can not be deregistered"));
        }
    }

    @Test
    public void testCreateBuiltinFunction() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function sin as 'org.apache.iotdb.db.query.udf.example.Adder'");
            fail();
        } catch (SQLException throwable) {
            assertTrue(throwable.getMessage().contains("the same name UDF has been created"));
        }
    }

    @Test
    public void testReflectBuiltinFunction() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function adder as 'org.apache.iotdb.db.query.udf.example.Adder'");
            statement.executeQuery("select adder(*, *) from root.vehicle");
            statement.execute("drop function adder");
        } catch (SQLException throwable) {
            fail(throwable.getMessage());
        }
    }

    @Test
    public void testShowBuiltinFunction() {
        try (Connection connection = EnvFactory.getEnv().getConnection();
             Statement statement = connection.createStatement()) {
            statement.execute("create function udf as 'org.apache.iotdb.db.query.udf.example.Adder'");

            try (ResultSet resultSet = statement.executeQuery("show functions")) {
                assertEquals(3, resultSet.getMetaData().getColumnCount());
                int count = 0;
                while (resultSet.next()) {
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 1; i <= resultSet.getMetaData().getColumnCount(); ++i) {
                        stringBuilder.append(resultSet.getString(i)).append(",");
                    }
                    String result = stringBuilder.toString();
                    if (result.contains(FUNCTION_TYPE_NATIVE)) {
                        continue;
                    }

                    if (result.contains(FUNCTION_TYPE_EXTERNAL_UDTF)) {
                        Assert.assertEquals(
                                String.format(
                                        "UDF,%s,org.apache.iotdb.db.query.udf.example.Adder,",
                                        FUNCTION_TYPE_EXTERNAL_UDTF),
                                result);
                        ++count;
                    } else if (result.contains(FUNCTION_TYPE_BUILTIN_UDTF)) {
                        ++count;
                    }
                }
                Assert.assertEquals(1 + BUILTIN_FUNCTIONS_COUNT, count);
                statement.execute("drop function udf");
            }
        } catch (SQLException throwable) {
            fail(throwable.getMessage());
        }
    }
}
